Some runways, e.g., in Russia or Afghanistan, are of a design or for other reasons, capable of causing heavy use and shorted life of the landing gear of aerospace vehicles. More specifically, in many third-world or remotely located cities, the runways suffer from frost heave in which the frozen ground displaced portions of the runway. As such, displacement between portions of the runway causes the runway to be bumpy and rough. When an aircraft lands on these rough runways, the landing gear pivot joints absorb forces applied to the landing aircraft by the bumps. As the joints absorb the force, components of the joint (e.g., bearings) are heated and can be thermally affected (e.g., in or between the components). Lubricants with lead additives in the landing gear joints provide some protection for such joints, however, lead additives can no longer be used due to their environmental concerns.
Polytetrafluoroethylene (PTFE) liners or grease with PTFE particles have also been used, typically positioned in the landing gear joints in place of the lead lubricants, however, use of PTFE was discontinued in favor of more frequent lubrication of the joints. Even with more frequent lubrication, in colder climates, heated tents may need to be employed, positioned about the landing gear joints, to warm the landing gear to allow the lubricant to be pumped in. Nonetheless, components in the landing gear are expensive and time-consuming, which can include in some circumstances, replacement each month, as constantly needing to lubricate the assembly. The problem with rough runways and the effect on landing gear has been around for decades, and an acceptable, long-term solution has not yet been discovered.